Fairfax County Considers Intensely Developed Area (IDA) Designation for Tyson's Corner

After the July 7, 2003 adoption of its Chesapeake Bay Preservation Ordinance amendments, which significantly increased Fairfax's Resource Protection Areas (RPAs), the Board of Supervisors asked County staff to consider the implementation of Intensely Developed Areas (IDAs) in portions of Fairfax County. The IDA designation makes it more likely that encroachments in the buffer portion of the RPA can be achieved, increasing the usable area of some land parcels.

An IDA is an area of existing development and infill sites where little of the natural environment remains and which meets at least one of the three following criteria: "(1) development has severely altered the natural state of the area such that it has more than 50 percent impervious surface; (2) public sewer and water, or a constructed stormwater drainage system, or both, serve the area; and/or (3) housing density is equal to or greater than four dwelling units per acre."

The proposal to map Tyson's Corner as an IDA has the backing of County staff, who released their staff report and draft CBPO amendments (Page 6 of Staff Report) on the topic on July 21, 2003. In this report County staff noted, "based on development as of March 22, 1993, it is staff's view that the Tyson's Corner Urban Center would, in aggregate as a defined land area, meet one or more of the above IDA designation criteria." This IDA designation would not supercede existing Environmental Quality Corridors (EQCs) within the Tyson's Urban Center that were preserved through prior rezonings, however.

The Route 28 Tax District and the Dulles Corridor were also up for IDA consideration, but County staff dismissed those areas citing they do not meet the criteria of an IDA.

PERFORMANCE CRITERIA2

Proposed mitigation performance criteria for high-quality RPA encroaching development within IDAs:
  1. Water Quality Impact Assessments shall be submitted for any such encroachments;
  2. Consideration shall be given to the environmental goals and objectives of the adopted Comprehensive Plan for the subject property;
  3. The RPA buffer area shall be established to the extent feasible consistent with the proposed development or redevelopment of the site;
  4. Where practicable, a vegetated area that will maximize water quality protection, mitigate the effects of the buffer encroachment, and is equal to the area of the encroachment into the RPA shall be established elsewhere on the lot or parcel; and
  5. One or more measures shall be provided to mitigate the water quality impacts of the encroachment into the RPA.
Existing IDA performance criteria for all development within IDAs:
  1. Any development within an IDA would be required to achieve a 10% reduction in phosphorus loadings relative to existing conditions or not increase the phosphorus loadings relative to existing conditions if the site is currently and adequately served by Best Management Practices (BMPs);
  2. New development could be permitted within an RPA subject to approval of a Water Quality Impact Statement;
  3. Local governments are free to "exercise discretion regarding whether to require establishment of vegetation in the 100-foot-wide buffer area, but requires that consideration be given to implementing measures that would establish vegetation in the buffer in these areas over time in order to maximize water quality protection, pollutant removal, and water resource conservation."
With these exceptions, property development within IDAs would be subject to the same requirements as those properties outside the designation. To address the fairness issue of requiring stricter water quality regulations for minimal and in-fill development within Tyson's IDA that do not affect RPAs versus those sites that do impact RPAs, County staff is proposing a comprehensive IDA-wide or other area-wide BMP program be established to help effect a more level playing field for all development endeavors within IDAs.

HEARING SCHEDULE

A Fairfax County Planning Commission public hearing is scheduled for September 25, 2003 at 8:15 p.m. and a Board of Supervisors hearing is set for October 20, 2003 at 5:30 p.m. at the Fairfax County Government Center to consider the staff's and the Board's recommendations on the issues.

If you have any questions or need further information on this topic as it relates to your project, contact Frank Graziano or Mike Rolband.

1Fairfax County Department of Public Works and Environmental Services July 21, 2003 Staff   Report.
2The criteria can be found in the July 21, 2003 Staff Report of this subject.